PETER LLOYD: Mental health laws have been introduced in Western Australia today that will allow some teenagers to consent to electric shock treatment.

Under the new laws, children as young as 14 can agree to what's now known as electro-convulsive therapy.

The Barnett Government says the laws give patients greater say in their treatment but the medical profession is divided on the benefits of this type of therapy.

From Perth, Caitlyn Gribbin reports.

CAITLYN GRIBBIN: Electric shock therapy, as it's often referred to, is described by many psychiatrists as a last-resort medical treatment.

It induces controlled seizures in a patient as electric currents are passed through electrodes placed on the head.

It's used to treat severe depression, bipolar and schizophrenia, but exactly how it works remains a mystery.

GARRY WALTER: While the precise mechanism is unknown, the same is true of many treatments in medicine. It would seem that the production of a seizure is important for its effectiveness. More importantly, it's a treatment that has been shown over many decades to be safe and effective.

CAITLYN GRIBBIN: Professor Garry Walter is the chair of Child and Adolescent Psychiatry at the University of Sydney.

Today, electro-convulsive therapy or ECT in children is back in the spotlight. WA Health Minister Kim Hames introduced the new Mental Health Bill this afternoon.

A controversial element of that bill is laws that will allow children to consent to ECT from age 14.

Mr Hames says the bill provides support for patients, families and carers.

KIM HAMES: The bill is a progressive and effective tool to, first and foremost, promote and protect the rights of the persons with severe mental illness, in addition to, importantly, promoting access to mental health treatment, care and support.

CAITLYN GRIBBIN: But the medical profession is divided on the issue.

Doctor Judy Hyde is the president of the Australian Clinical Psychology Association.

JUDY HYDE: I know that I certainly have patients who, I seriously believe, would not be alive today had they not undergone this treatment. However, I do have a patient who has serious memory problems as a result of the treatment.

A 14 year-old who is depressed, suicidal, is not in a position to be able to make a decision that is objective. It's quite a serious thing to be thinking about and should only be done in the most exceptional of circumstances.

CAITLYN GRIBBIN: Wouldn't that decision be made with the help of a doctor and of the child's parents?

JUDY HYDE: Certainly in many cases it would, but if you consider what it would be like to have a very depressed, suicidal adolescent, you're desperate.

CAITLYN GRIBBIN: Professor Paul Skerritt is a psychiatrist and spokesman for the Australian Medical Association.

He says people shouldn't be worried about electric shock treatment.

PAUL SKERRITT: The evidence for safety was established before the treatment was introduced. The treatment was given to a very large number of dogs in Italy before it was given to humans and it was established that you could cut these dogs' brains up and there was absolutely no evidence of any damage whatsoever, so that's complete mass hysteria.

CAITLYN GRIBBIN: Is it proven that ECT is beneficial for children?

PAUL SKERRITT: No, because it's something that is done exceedingly rarely. You know, it's really an irrelevancy about giving to children. If it is given to children, it would be in highly exceptional circumstances and in circumstances that are so rare that it would be impossible to provide that sort of proof.

CAITLYN GRIBBIN: WA's Commissioner for Children and Young People, Michelle Scott, provided a submission to the Government about ECT. She said the therapy should be prohibited for all children and young people.

Ms Scott said if ECT was to remain in young people, the age limit should be lifted to 16.

Professor Garry Walter, the chair of Child and Adolescent Psychiatry, has also published a book on the issue. He says there's no evidence that electro-convulsive therapy is dangerous in children, but says there are some side effects.

GARRY WALTER: Transient headaches, temporary and mild confusion and memory problems which go over the course of treatment.

CAITLYN GRIBBIN: One of the criticisms of this therapy is, for example: it can lead to memory loss?

GARRY WALTER: There is no evidence that ECT in young people leads to permanent memory loss or any other damage to the mind or brain.